An organic light emitting display (OLED) does not need backlight due to its self-luminous property, so it can be used as a transparent display. One type of the transparent display device in the related art includes both a cathode and anode of luminous pixel adopting a transparent material. As shown in FIG. 1, the transparent display device having high transmittance will cause the brightness at the display side to be significantly reduced, thus reducing contrast of the display panel. Moreover, it is suitable for the luminous pixel of the transparent display device to adopt a side-by-side lighting manner, which requires Fine metal mask (FMM), such that it is not suitable for fabricating a large size display panel.